LOCK-SCREW 5M6648 - Caterpillar

The quick-disconnect sealed cap fits directly on any of these nipples as shown.Being able to quickly seal a leaking nipple can prevent machine downtime. The nipple can be flushed clean later or replaced during scheduled maintenance. The nipples listed are all those used on Cat products. They are found on several fluid systems and on diagnostic tooling and shop equipment. Dealer and user personnel who do diagnostic work or S O S oil sampling should have a few sealed caps with them for immediate installation. The sealed caps are not installed at the factory. The specifications of the 8C8456 Sealed Cap are:Operating Pressure; 42 000 kPa (6100 psi)Minimum Burst Pressure; 168 000 kPa (24,000 psi)Operating Temperature; -34°to 107°C (-29 to 225°F)Seal Material; Buna-N® (High Temperature)
The new cap will fit all nipples currently used. These nipples are in the following two lists.
... 6V3965: 9/16"-18 External Thd. for No. 6 Port, Amber or Brass Color, with Buna-N® Valve Seal.... 6V3966: 1/4"-NPTF External Thd., Amber or Brass Color, with Buna-N® valve seal.... 6V3989: 1/4"-NPTF Internal Thd., Amber or Brass Color, No Valve.... 6V4142: 1/8"-NPTF Internal Thd., Amber or Brass Color, No Valve.... 6V4433: 9/16"-18 External Thd. for No. 6 Port, Light Green Color, with Viton® Valve Seal.... 6V7691: 1/4"-NPTF External Thd., Light Red Color, with Ethylene Propylene Valve Seal.... 8T3613: 1/8"-NPTF External Thd., Amber or Brass Color, with Buna-N® Valve Seal.... 8T3614: 1/8"-NPTF External Thd., Light Red Color, Ethylene Proplene Valve Seal.... 8C3345: M10 by 1-2g External Thd., Amber or Brass Color, with Buna-N® Valve Seal.... 8C3446: 7/16"-20 External Thd. for No. 4 Port, Amber or Brass Color, with Buna-N® Valve Seal.... 7X3387: 1/4"-NPTF External Thd., Amber or Brass Color, with Viton® Valve Seal.